Here are some links to the IRS website:
http://www.irs.gov/Individuals/Get-Transcript
http://www.irs.gov/taxtopics/tc159.html
It isn't clear whether you need a copy of your return or your W-2 but you can get all of the information from the IRS. If you just need your W-2 and you are working for the same employer, you may want to see if HR can get you a copy quickly, though.